Weeds won’t win
Pampas Grass (Cortaderia species)
What is it?
Pampas are large, vigorous, dense, tussocky perennial grasses. There are more than
20 species of Pampas grass. Most of these originate in South America, but some are
native to New Guinea and New Zealand. Pampas were introduced to Tasmania as
shelter belt plants on farms and as ornamentals in parks and gardens. Three of
these species have naturalized in Tasmania. They are Cortaderia selloana (common
pampas grass), C. jubata (pink pampas grass) and C. richardii (New Zealand pampas,
toe toe).
Cortaderia selloana
Common pampas
Tussock
Leaf
Leaf sheath
Stems
Roots
Flowers
Reproduction
Germination
Flowering
C. jubata
Pink Pampas
C. richardii
NZ Pampas
2m high. 1 to 1.5m
across
1.5 -2m high. 1-1.5m
across
To 3m high. 1-1.5m
across
Many, finely serrated,
sharp edged, curving
blade to 2m long,
tapering,
2-3.5cm wide, distinct
midrib top surface
(blue-green) paler than
undersurface (dark
green)
No midrib
Smooth or few hairs,
not waxy
Multiple long, erect,
hollow stems of 2-3cm
diameter which reach 2
to 4 m high
(occasionally to 6m)
Many, sharp edged
curving blade to 2m
long, tapering, 2-3 cm
wide, distinct midrib,
dark green
Many, finely
serrated, sharp
edged
curving to 2m long
Distinct midrib and
secondary veins
1-2 cm wide
blue-green, paler
top surface
Distinct midrib,
waxy white
covering
Multiple long, erect,
hollow stems to
2cm diameter
which reach 2 to 5
m high
30 – 90cm long white,
pink – mauve produce
pale – straw coloured
seed
Gynodecious (separate
female and bisexual
plants). Female plants
require cross pollination
by bisexual plants.
Spring
March -May
No midrib
Hairy, not waxy
Multiple long, erect,
hollow stems of 2-3cm
diameter which reach 2
to 4 m high
Massive to 3.5m depth
30 – 90cm long purple
(fades to brown)
produce pale – straw to
brown seed
Plants are female and
apomictic (can
reproduce without
being fertilized)
Spring
Jan – mid March
Seed already nearly
mature before flowering
Department of Primary Industries & Water
30 – 90cm long,
sparse, pale gold
produce pale –
straw to brown
seed
Female and bisexual
plants. Female
plants require cross
pollination by
bisexual plants
Autumn
Nov - Jan
Key Points
• Prevention is the
most cost-effective
means of weed
control
• Long-term control
of pampas is best
achieved by using a
combination of
control methods.
Pampas damages
native bush &
wetlands
• The key to
controlling the
spread of pampas
is to prevent
flowering.
Weeds won’t win
Pampas Grass (Cortaderia species)
How it spreads?
Pampas primarily reproduce by seed but can grow from root segments. Seed
production is highly prolific with up to 100,000 seeds per flower head. Seeds are
light and can be windblown to 25km. An individual plant therefore has a
tremendous potential to spread.
What are its impacts?
Pampas is highly invasive. It is capable of infesting otherwise healthy and intact
native vegetation, from clearings in forest to grasslands and wetlands.
Established plants will then out-compete native plants for nutrient, water and light.
Over time this means that Pampas plants become bigger, more numerous.
Native plants are threatened as they lose the battle for space and resources and fail
to reproduce. The large amount of leaf and stem material produced by pampas
plants makes them, additionally, a significant fire hazard.
Key Points
• Prevention is the
most cost-effective
Where might it be found in Tasmania?
Cortaderia selloana (common pampas grass), C. jubata (pink pampas grass) have
means of weed
naturalized across Tasmania including Flinders Island. C. richardii (NZ pampas) is
control
confined to the west coast.
What to do about it?
Stopping seed production is the key to stopping the spread of pampas grass. Site
factors will influence the choice of control method. Physical removal is effective.
Small plants can be removed manually while machinery will be required for larger,
mature plants. There are effective herbicides registered for control of Pampas in
Tasmania. A control strategy with both physical and chemical measures can also be
effective. Larger plants can be slashed to reduce mass and reduce the amount of
herbicide required - ensure seed heads are removed, securely bagged and buried
first, though, before spraying. Plants can also be burnt, with care, but will need
some new growth prior to herbicide application. Pampas can be controlled
through application of a registered herbicide in accordance with label direction.
Useful links:
The following links may prove useful to the serious weeds enquirer. They contain
information about weeds and related issues:
Statutory Management Plan for Pampas Grass –
http://www.dpiw.tas.gov.au/inter.nsf/WebPages/LBUN-5DE2AN?open
• Long-term control
of pampas is best
achieved by using a
combination of
control methods.
Pampas damages
native bush &
wetlands
• The key to
controlling the
spread of pampas
is to prevent
flowering.
DPIW Useful Weed Resources www.dpiw.tas.gov.au/inter.nsf/WebPages/TPRY-4ZV5H4?open Department of Primary Industries & Water